Feature/sm list of users

Unit test  cases  for section_details method  This method displays list of enrollments on a section id being passed in. 
Most of the test cases were developed by  all 3 of us (Carter, Josie, Sapna) in a developer working session.
Ah - here it is. If you're comfortable that you don't want to accept the string representation of a number, feel free to ignore my last comment.